Electromagnetic sparking plug.



No. 895,958. PATENTED AUG. 11, 1908.

O. CARLBORG.

ELECTROMAGNETIC SPARK'ING PLUG. APPLICATION FILED JUNE 9,1906.

. INVENTUR. .Oiio (tm'lbovq UNITED STATES PATENT OFFICE.

OTTO OARLBORG, OF PROVIDENCE, RHODE ISLAND.

ELECTROMAGNETIC SPARKING PLUG.

To all whom it may concern:

Be it known that I, OTTo OARLBORG, a citizen of the United States of America, and a resident of Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvemerits in Electromagnetic Sparking Plugs, of which the following is a specification.

My invention relates to improvements in magnetic sparking-plugs, so-called, that is devices of the class adapted to be mounted in the heads of cylinders of explosive-engines; the plugs when in use being electrically connected with intermittingly actuated magnetos which generate the electric current employed and also control the action or movements of the circuit-breaking contacts of the plugs mounted in the heads of the cylinders and extending into the explosionchambers thereof.

In sparking-plugs as usually constructed the comparatively high temperature produced in the explosion-chamber of the cylin der by the combustion of the gas is conducted through the adjacent wall or head of the cylinder to the plug itself thereby to some extent impairing the latters eificiency. In former sparking-plugs the inner end or lower part of the shank or stem portions of the movable electrodes of the circuit-breaking contacts were mounted to swing in removably secured metal bearings or bushings, and these latter, owing to the high degree of heat generated as above stated, and the consequent lack of proper lubrication wear out or become cut in a comparatively short time, thereby necessitating their removal and the substitution of new ones.

The object I have in view is to produce a sparking-plug of the class above referred to in which the objections or disadvantages just named are practically eliminated, thereby correspondingly increasing the efficiency and durability of the plug.

To this end my invention consists essentially in providing the sparking-plug with an open space between its upper and lower portions for the free circulation of cooling air, thereby to a great extent preventing the heat from the lower section from being conducted to the upper one. In lieu of a metal bearing for the shank of the movable or swinging electrode the lower section of the plug is provided with a suitably drilled, cut and mount ed bearing made of a comparatively inexpensive natural hard stone, as agate.

This latter Specification of Letters Patent.

Application filed June 9, 1906 Patented Aug. 11, 1908.

Serial No. 320,972.

material is practically unaffected by the action of the electric current and the heat to which it is or may be subjected and forms an efficient, durable and substantially frictionless seat and bearing for the said movable electrode.

In the accompanying sheet of drawings, Figure 1 represents a side or front elevation of a magnetic or electro-magnetic sparkingplug embodying my improvements, the outer casing or cap being in section. The plug, as drawn, is disconnected from the engine and magneto or current generating device but capable of being connected therewith. Fig. 2 is a partial horizontal sectional view taken on line 2 2 of Fig. 1. Fig. 3 is an inverted )lan View, corresponding with Fig. 1, and

ig. 4 is a partial vertical or longitudinal sec tional view (in enlarged scale) taken through the lower portion of the movable electrode member and its bearing, &c.

I would state here that with the exception of my present improvements the device A illustrated in Fig. 1 represents a well-known example of the type of electro-magnetic sparking plugs adapted for explosive engmes. In this as in other analogous devices the lower or screw-threaded shank portion a or plug proper, integral with and extending below the base a, is adapted to be screwed into the head of the cylinder or explosionchamber of the engine. The body portion a of the other or upper section is cylindrical and usually integral with said lower section and being without the intervening air space 3. The upper section is normally provided with a pair of finely wound magnets, as m m, a spring-retracting swinging armature (Z having a pin d on its lower end, a fixed stop 0 and the two circuit-breaking contact members or electrodes 1 and f. The latter member is arranged to swing on its axis and has an integral shaft or stem f extending upwardly therefrom through said lower and upper sections and is provided with a springpressed lever 7L secured to its top end. See Fig. 2-. One terminal of the said magnets is secured to the conducting post r in electrical connection with the said vertical stationary electrode r, the latter extending downwardly through the two sections and being insulated therefrom, its lower end adapted to be normally engaged by the free end of the movable contact member f, the electric circuit then obviously being closed. An insulated member or non-conductor Z is secured to the base a and is adapted to receive and hold therein a conducting wire, indicated at n, for conducting the current of electricity, generated by any suitable intermittingly operating magneto device, not shown, to the other terminal of said magnets m, thereby correspondingly energizing them. In my invention the plug A is made in two connected main parts, a and a which may be termed upper and lower sections, thereby forming between them a comparatively large s )ace 8 for the free circulation of cooling air. 11 order to further increase the cooling surface a number of parallel horizontally arranged stationary heat-radiating plates 2) of metal may be located in said space .9. In this arrangement the shaft f of the movable crlintact member f passes freely tln'ough the p ates.

My invention also resides in the novel manner of mounting the lower portion of the said shaft f, shown more clearly in Fig. 4. The plug portion a is bored longitudinally to freely receive the shaft and is counterbored, a metal sleeve or bushing i being secured therein. As drawn, the bushing itself is also counterbored and arranged to hold therein the annular bearing member is of suitable non-metallic material. I prefer to use for the purpose a hard natural stone, as agate. The hub portion of the movable electrode is enlarged, its upper end being reduced in diameter and forming a beveled part f intersecting the smaller or straight shank portion f, all being integral. The lower or outer end of the said bearing member 7c is beveled at k contiguous to the hole to fit the corresponding part f of the electrode. The metal of the lower inner edge of the bushing i may be pressed inwardly in any suitable way upon the adjacent part of the bearing 76, as indicated at 0, so as to firmly maintain the latter in position.

When sparking-plugs or devices of the character described are suitably mounted and connected, as in use, the magnets m thereof are normally non-energized, the corresponding relation of the movable members being then substantially as represented in the several figures, the two electrodes 1" and f being in actual contact with each other. Upon the passage of an electric current from its source of supply 'or generation via the conductor 72 and suitable connections leading therefrom to the magnets the latter become energized thereby attracting the swinging armature or key (Z and causing the pin (2 thereof to advance and engage the free end of the horizontal lever member h rigidly secured to the upper end of the movable contact or electrode shaft f, the result being to swing the electrode away from the fixed fellow contact member 9 thereby arcing or producing an electric spark between them at the instant the circuit is broken. The correspending position is indicated by dotted lines in Fig. 3. The movable parts instantly and automatically return to the normal or closed position whenever the magnet-energizing circuit is broken.

hen the device or spa'rkingplug A is in service, as just stated, its normal operation is one impulse per revolution of a two-cycle engine and one for every two revolutions for a fourcycle engine, thereby producing corresponding explosions of gas in the combustion-chamber of the engine. As the electrodes are necessarily mounted in said chamber they are directly subjected to the internal heat thus generated, but owing to the presence of the improved bearing 7c in which the movable electrode is mounted the latters efficiency and freedom of movement are not appreciably lessened. The higher temperature of the thus heated lower plug section a is prevented from being conducted to the upper or exterior section by reason of the air-circulating space 8 formed between the connected sections.

I am aware that rock-shafts carrying the movable electrodes of sparking igniters have heretofore been mounted to oscillate in both insulated and non-insulated bearings of the plug portion, and I therefore disclaim such former construction broadly. In my device, however, the bushing member 01 of suitable material, as bronze, is removably secured in the counterbored base of the plug the member i itself being counterbored to receive therein the annulus 7c of hard non-wearing material, and having the latter arranged to form a combined seat and oilless bearing for the rock-shaft f of the electrode or contact member f.

I claim as my invention and desire to secure by United States Letters-Patent:-

1. In an electro-magnetic sparking-plug of the character described, the combination with a lower section or plug member proper adapted to be removably secured to the cyl inder of an explosive engine, and normally contacting fixed and movable electrodes mounted in said section, of an upper section secured to said lower section so as to produce a comparatively large open air-circulating space between their adjacent ends, an electro-magnet and armature mounted in said upper section and operatively connected with said electrodes so that when in use upon energizing the magnet the resulting movements of its armature automatically separate said electrodes to produce an elect'ic spark, the heat from the plug at the same time being materially reduced or tempered by air circulating in the said open space, substantially as described.

2. In a sparking-plug of the character described, the combination with upper and lower suitably united sections separated longitudinally so as to form a substantially unobstructed air-circulating space 8 between them, of a series of fixed heat-radiating plates interposed between the sections and located in said air space, substantially as described and for the purpose set forth.

3. In a sparking-plug or electric igniter, the combination with a stationary plug section proper, an electromagnetic device, and a stationary electrode projecting from the underside of the said plug section, of a rockshaft extending downwardly through said plug section adapted to be actuated by said electromagnetic device when the latter is energized, an electrode member secured to or integral with the lower portion of said rockshaft and normally engaging said stationary electrode, the upper end or face of the hub of the movable electrode being enlarged to form a shoulder, a bored bushing 73 of suitable metal fixed in the lower part of the plug sec- OTTO CARLBORG.

WVitnesses:

GEO. H. REMINGTON, CALVIN H. BROWN. 

